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The interleukin-2 receptor (IL-2R) gamma chain (gamma c chain) is shared by IL-4R, IL-7R, IL-9R, and IL-15R and plays an important role in regulation of the immune system. However, its regulation in monocytic cell lines has not been well clarified. We examined the expression and regulation of the IL-2R alpha, IL-2R beta, gamma c chain, IL-4R and IL-7R mRNA in a human monoblastic leukemia cell line, THP-1. Unstimulated THP-1 cells constitutively expressed a low level of gamma c chain and IL-4R mRNA. Phorbol myristate acetate (PMA) induced macrophage-like differentiation and up-regulated the gamma c chain mRNA expression in THP-1 cells. This effect of PMA was suppressed by the protein kinase inhibitors H-7 and staurosporine. PMA did not affect the expression of the other IL-R mRNAs examined. 1 alpha, 25(OH)2D3 and interferon-gamma also induced differentiation of THP-1 cells, but these reagents did not affect the expression of the IL-R mRNAs in THP-1 cells. These findings suggest that the expression of the gamma c chain mRNA is regulated by the PMA-dependent pathway and is not associated with that of the other IL-R mRNAs.

In the therapy for early gastric cancer, Endoscopic diagnosis is essential. When early gastric cancer is diagnosed within certain range, it is possible to be cured without surgery only endoscopic therapy. Indication for now endoscopic therapy is limited lesion which is well differentiated adenocarcinoma not more than 2 cm in size with mucosal infiltration but no ulceration. In the endoscopic therapy, it is important to detect serial multiple occurrence of early gastric cancer and recurrence of residual cancerous lesion. For these problems, annual endoscopic examination is needed.

Early gastric cancer detection is still in its more elementary step in the western hemisphere, while in Japan gastric cancer is detected mainly in its early stage. The aim of this article is to analyze the Japanese method for early gastric cancer detection and staging, by sketch of certain morphologic criterions and a report of a typical case. In our case the lesion's staging was predicted as submucosal by means of endoscopy and double contrast roentgenography. Endoscopic ultrasonography complemented the analysis. The standard anatomopathological work up for early gastric cancer in Japan is also analysed. By this former method the accuracy of the initial staging by endoscopy, and radiologic means was ensured. By a correct early gastric cancer diagnosis and staging a better selection of the surgical strategy and survival can be achieved.

This paper proposes a method for determining Young's modulus of a magnetic medium for which Young's modulus of thin films composing it can not be measured directly. The particular internal stresses induced in bonded two thin films under tension are analysed by the finite element method (FEM). Among these stresses, the importance of shearing stress induced at the interface between two thin films is indicated.

The purpose of this study was to clarify the significance of immunohistological staining for PCNA/cyclin in human colorectal lesions. Our results: The PCNA-positive cells existed at the bottom of colonic tubuli in the normal and hyperplastic conditions. In the neoplastic lesions, however, the positive cells were existed at the relatively surface of the mucosa (chi 2: P less than 0.01) and distributed irregularly from the bottom to the top of carcinoma tissue. These results suggested that immunohistological staining for PCNA would specifically detect the cell proliferation and be beneficial for practical use and clinical application of the diagnosis of the colorectal lesions.

The strategy for peptic ulcer therapy has been changing with the clinical application of the gastric proton pump inhibitor (PPI). In Japan, Miyoshi et al and Takemoto et al reported an earlier reepithelialization of peptic ulcer with omeprazole (OME) or lansoprazole (LAN) than famotidine (FAM). Miyoshi et al also reported that there was no significant difference between OME and FAM in ulcer relapse rate during a one year follow-up period. Therefore, there were two problems. One is application of PPI for prevention of ulcer relapse, and the other is the more accurate diagnosis of ulcer healing. Application of PPI for maintenance therapy is not yet realized in Japan, but, Lauritsen et al had already reported on the efficacy and safety of OME, 20 mg, three days a week and 10 mg, daily in prevention of duodenal ulcer relapse. Reepithelialization (red scar) is already established as a starting point of maintenance therapy, and from Miyake's report, a white scar is believed a favorable (non relapsing) end point.

Physical training is generally considered to increase serum high density lipoprotein cholesterol (HDL-C) levels.1 However, how exhaustive training influences serum HDL-C levels remains unknown. Intense exercise increases oxygen consumption and free radical formation, and induces oxidation of low density lipoprotein (LDL).2 HDL plays an important protective role in LDL oxidation.3 An imbalance between free radical production and antioxidants is considered to lead to oxidation of LDL and subsequent alterations in serum HDL metabolism. This study investigates changes in serum urate, which is the most important intrinsic antioxidant,4 and serum lipids in male athletes after three weeks of exhaustive training. We measured fasting serum lipids …

Corrugated waveguides and lasers in resonant and non-resonant situations are analyzed by an improved coupled mode theory based on a set of the coupled mode equations for guided modes and radiation continuum. The distributed feedback (DFB) coefficient and the radiation loss coefficient are given in closed forms. The formulation can be applicable to arbitrarily shaped gratings and multilayer waveguide structures. The accuracy of the theory is examined by comparing it with Tamir's exact calculation for a nonresonant situation and also with Streifer's one for a DFB structure. Reasonable accuracy is obtained by the proper choice of the unperturbed waveguide parameter. The dependence of the two coefficients on the grating depth, the grating period, the guide layer thickness, and the refractive index difference between core and cladding layers is obtained for all Bragg orders up to the fourth, and for four typical grating shapes, namely, for rectangular, sinusoidal, symmetric triangular, and sawtooth gratings. Both the threshold gain of DFB lasers utilizing higher order Bragg reflection and the output coupling efficiency of grating beam couplers are also calculated for these parameters. A new multilayer structure for controlling the radiation loss is proposed and analyzed. This structure is suitable for the suppression of the radiation loss in DBR reflectors as well as for the improvement of the output coupling efficiency in grating beam couplers.

This paper describes the recent progress in research and development of fiber optics in Japan. A review is presented of recent developments in fiber manufacturing, cabling, and fiber splicing. Experimental results are given for an optical communication system with optoelectronic components. Theoretical analysis and fundamental experiments are not included, nor are research activities in such devices as lasers or in such applications as those in medical fields. Transmission characteristics of optical fibers—in particular loss and pulse spreading—are assessed from the viewpoint of their structures. Various methods of fiber strengthening and structuring cables are described from the viewpoint of mechanical strength. Coupling efficiencies of detachable connectors and methods of permanent fiber splicing are described. Experimental results on optical fiber communication systems are presented and coupling techniques between a light source and an optical fiber are described.

A family of near-field spot excitation or detection techniques have recently been developed to measure the refractive index profile of optical fibers. The present paper discusses the effect of finite spot size of the illuminating beam on the accuracy of the reconstructed profile. A wave theoretical analysis is performed, and a series of numerical examples are given. Experiments of the spot excitation near-field scanning method are performed for a nearly parabolic index fiber, resulting in a satisfactory agreement with the numerical analysis. Furthermore, a quantity is introduced which is a function of the refractive index, wavelength, and spot size of the illuminating beam. This quantity serves to determine the suitable spot size for measuring the optical fibers having different parameters.

An efficient technique for the modeling of I2L devices is developed on the basis of quasi-three-dimensional (Q3D) models, where a device is represented by several one-dimensional model units and the network which combines them. This improved method is capable of treating both dc and ac characteristics within a reasonable computation time. The computed and experimental results are compared, and good agreement is obtained. The importance of high injection effects and lateral voltage drops is clarified for the β up falloff of multicollector I2L devices at high current levels. The difference between downward and upward operation of the vertical transistor is pointed out. The possibility of applying this method to the optimization of device structure is also shown.

The theory is developed for the characteristics of a Schottky-barrier-gate Gunn-effect digital-device (SBG GEDD). The four basic parameters, i.e., relative field drop, minimum trigger-field, minimum trigger-pulse duration, and trigger capability, are defined and evaluated numerically for GaAs. Then the device characteristics such as output current, maximum trigger sensitivity, trigger capability, amplification factor, fan-out, noise margin, jitter, unidirectionality, and power-delay product, are derived and calculated for SBG GEDD's with different doping densities and different sizes by using the results of preliminary measurements. The features of SBG GEDD are 1) great trigger capability, 2) good trigger sensitivity, 3) high unidirectionality, 4) small input capacitance, 5) high response-speed and short delay time, 6) small power-delay product, 7) large fan-out, and 8) simple device and circuit constructions. Some applications are demonstrated to high-speed pulse repeaters and logic circuits.

In the previous paper [1] we proposed an accurate formalism for analyzing corrugated waveguide devices. This formalism, developed for the TE modes, is extended here to TM modes. Characteristics of TM modes in distributed feedback (DFB) lasers, DBR reflectors, and grating beam couplers are investigated with emphasis on the effect of the radiation loss and they are compared with the TE case.

A numerical analysis of GaAs MESFETs with a p-buffer layer on a semi-insulating substrate is performed in which impurity compensation by traps in the substrate is considered. It is shown that the use of a thick p-buffer layer results in a lower device current due to the formation of a steep barrier at the channel-substrate interface. It is also shown that with higher trap and acceptor densities in the substrate, the drain current is reduced due to the decrease in the substrate current. This decrease occurs because a negative-space-charge layer is formed in the substrate. It is demonstrated that when the p-buffer layer is fully depleted, its acceptors play the same electrical role as the acceptors within the space-charge region of the semi-insulating substrate. Thus, using a thick p-buffer layer has the same effect as using a substrate with a high density of traps, i.e. it minimizes the short-channel effects in GaAs MESFETs. Therefore, if the trap density in the substrate is low, the short-channel effects can be reduced by introducing a p-buffer layer or a buried p-layer. >

The dependence of the phase shift of the light output from sinusoidally modulated semiconductor lasers was investigated as a function of the modulation current. This measurement is effective in accurately determining the short damping time constant associated with the relaxation oscillation. The frequency half width of this phase shift \Delta f was found to be inversely proportional to the damping time constant. For narrow stripe lasers, the phase shift occurs more gradually, which corresponds to the fact that the narrow stripe lasers have shorter damping time constants. To analyze the narrow stripe effect, the recently developed time-dependent self-consistent theory was applied, considering the transverse distribution of both optical field and carrier density and including the carrier diffusion term. This theory can explain the shorter damping time constant for narrow stripe lasers compared with broader stripe lasers.

Current-voltage characteristics and space-charge distributions in an n-i-n structure have been numerically analyzed and compared with Lampert's theory. It is found that an effective resistivity in the low-voltage region depends on acceptor and trap densities and the length of an i-layer. The analytical model has been presented to estimate the effective resistivity and the onset voltage for current rise. The back-gating effect also has been analyzed in terms of a separation distance between devices and an acceptor density. To achieve a good isolation between two devices in GaAs IC's, it is suggested that a shallow acceptor density as well as a trap density must be larger than a critical value.

The attenuation characteristics of a multilayer metal-clad optical guide, which is suitable for a mode filter or electrooptic devices, is investigated by the exact theory and the analytical approximation based on a perturbation technique. By using this approximation the dependences of the ohmic loss on the various waveguide parameters and the condition for the absorption peak of the TM mode are derived in closed form. Some remarks concerning the waveguide material and dimension for the design of the mode filter are also presented. The insertion loss at the abrupt junction between a normal (dielectric-clad) optical guide region and a metal-clad optical guide region is treated. Also the transformation of optical guided modes in the two kinds of tapered structures between the above two regions is examined.

At the high injection operation of double-heterostructure (DH) light emitting diodes (LED's), such specific phenomena as temperature rise, band filling, carrier overflow, and ambipolar diffusion affect the device performance. We present an accurate method of mea, suring temperature rise in Burrus-type LED's by using resonant reflection spectra. This method is superior, especially for the high injection region, to the conventional emission-spectrum method and junction-voltage method due to its band filling-free and injection-free properties. An accuracy of ±0.8 K has been obtained, which is four times better than that of the emission-spectrum method in the case of Burrus-type LED's. This improvement is accomplished by using the resonant spectra in an absorption-free infrared spectral region. Thermal properties including dynamic behavior can be characterized quantitatively by deriving the thermal resistance and the thermal time constant of the device.

Interface effects in GaAs MESFET's were investigated from the viewpoint of stability of performance. It was clarified, on the basis of a simple analytical model, that even a small fluctuation of the effective channel thickness due to interface effects causes drastic changes or drifts in performance characteristics of a GaAs MESFET. Paying attention mainly to the behavior of drain current, the interface effects were experimentally investigated for VPE-gown 1-µm-gate GaAs MESFET's with and without a buffer layer. It was revealed that they are due to deep acceptors or hole traps, which exist at the interfaces and in the buffer layer and the semi-insulating substrate, and found that the long-term drift is attributed to Cr in the buffer layer as well as in the semi-insulating substrate.

A computer program has been developed that simulates two-dimensional dynamics of electrons and holes in a p-channel charge-coupled device. By using this program we have investigated the effects of two-dimensional device structure on surface-charge transfer, particularly a potential-barrier and fringing field. We have obtained the following results: 1) in case of a p-channel CCD negative charges on the SiO 2 film at a gap reduce the potential-barrier between transfer electrodes. This effect aids transfer of surface-charge in a CCD with wide gaps. 2) In transfer operation of a CCD with wide gaps, the signal charge must be less than a particular value so that a potential-barrier does not emerge. The particular value depends upon the device parameters and the transfer pulses. 3) The fringing field created by the adjacent electrode enhances the speed of surface-charge transfer. This effect increases with decreasing the transfer-electrode length and the signal charge level. 4) The computer results indicate that 100 percent transfer efficiency is obtained from the strong fringing field after the transfer time is equal to the transit time if no surface states exist.

By using a Schottky-barrier-gate Gunn-effect digital device the direct modulation of a GaAs-Al x Ga 1-x As double-heterostructure laser was achieved with a rise time of 250 ps. The dependence of the optical waveforms on the bias-current levels was investigated in detail. The results are compared with a rate-equation analysis. A discrepancy between the present theory and the experiment indicates the existence of an additional relaxation mechanism.

Based on the multimode rate equations taking account of transverse mode and carrier density distributions, the axial mode behavior in semiconductor lasers is investigated. The axial mode stability is significantly affected by these distributions. Above threshold, because of hole burning in the carrier density distribution, the gain at any wavelength except the lasing wavelength does not maintain the value at threshold. If the nonlasing mode wavelength is located in the gain decreasing spectral region, its light output decreases with the increase of current. These characteristics are observed in the experiment for a CSP laser. For axial mode stabilization, a large built-in refractive index step is effective so long as single transverse mode operation is maintained. If the injection current region is defined separately from the guiding region, the wider width of the injection current region leads to a more stabilized axial mode.

A graphical procedure is presented to obtain an approximate solution to the minimization problem of the follwing form: Minimize the function $$\varphi (t_0 ,t_1 ,...,t_{n - 1} ,t_n ) = g(t_0 ,t_1 ) + g(t_1 ,t_2 ) + ... + g(t_{n - 1} ,t_n )$$ subject to the constraints $$t_0 \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{ \leqslant } 0< t_1< t_2< ...< t_{n - 1}< T\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{ \leqslant } t_n $$ wheren the number of the variables is not predetermined. The nomograph for the procedure is constructed of contour lines of the functiong(.,.) as well as two other auxiliary curves. Procedures to prepare such nomographs by computer are also presented. Es handelt sich um eine nomographische approximative Losungsmethode der folgenden Minimierungsaufgabe: $$g(t_0 ,t_1 ) + g(t_1 ,t_2 ) + ... + g(t_{n - 1} ,t_n ) = \min !$$ unter der Bedingung $$t_0 \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{ \leqslant } 0< t_1< t_2< ...< t_{n - 1}< T\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{ \leqslant } t_n ,$$ wobein die Anzahl der Variablen ist und auch unbekannt sein kann. Der Nomograph besteht aus den Hohenlinien vong(.,.) und anderen Hilfslinien. Die Erstellung der Nomographen durch Computer wird auch gezeigt.

石炭のコークス化時における押力は, コークス炉操業上きわめて重要な問題であるにかかわらず, わが国ではいまだ本質的な研究が行われていなかった。押力測定には可動壁炉が最も理想に近いので, 両面加熱可動壁炉の設計建造を行つた。 (1) 円筒に高膨脹性の三池炭を装入して加熱した結果, 加熱條件のいかんにかかわらず直径130mm以上では膨脹しない。この事実より可動壁炉の炉幅は130mm以上を必要とすることを知つた。 (2) 建造した可動壁炉の概要は, 炉幅170mm, 装炭量22.5kg, 電熱による両面加熱, 油圧式圧力計使用である。 (3) 測定値の標準偏差は三池炭の場合, 0.002kg/cm2以内で, Koppers社のRusselI炉の再現性0.02kg/cm2以内より良好である。その主因は炉が比較的軽快で摩擦抵抗が小さいためと考えられる。 (4) 試料を1100℃, 750℃, 500℃および室温の炉に装入して, 押力を測定した。

The "resonant mode" of oscillation of a Gunn oscillator is analyzed. Experimental results show the frequency of oscillation of the "quenched dipole mode" depends on the load admittance. These characteristics can be explained by a proposed model which considers the formation and extinction of a dipole layer due to the RF voltage excited in a resonant cavity. The discussion accounts for the time constant of the growth and decay of a dipole layer and derives the susceptance and negative conductance components of the diode model.

The survival factor of minority carriers is one of the important factors which determine the current amplification factor of a junction transistor, and is generally known to be much more affected by the surface recombination of the minority carriers than by the volume recombination in the base region. It is therefore quite necessary in the design of transistors to get an expression of the survival factor s in terms of the surface recombination velocity, the dimensions of the emitter and the collector electrodes, and the thickness of the base region. Because of the complexity of their geometries, however, analytical expressions of s have not yet been obtained for alloy junction and other similar types of transistors. In this paper, analytical formulas for various idealized geometries are derived by means of approximating methods. From these results, many useful design data such as the optimum radius ratio of the emitter electrode and the collector are obtained and the effect of curvature of the electrode surfaces is made clear. It is also pointed out that the survival factor can be expressed by four dimensionless quantities, thus establishing the principle of similitude among transistors having different surface recombination velocities and difflerent geometrical dimensions of electrodes. The values of s calculated from these formulas are in good agreement with the experimental values previously obtained by Stripp and Moore from an analogy of three-dimensional electrolytic conductance.

A parallel-plate waveguide model for the microstrip line formed on the Si-SiO/sub 2/ system is analyzed theoretically and the results are compared with the experiment. The experiment has been performed over wide ranges of frequency, substrate resistivity, and strip width. Existence of three types of fundamental modes is concluded and the condition for the appearance of each mode is clarified. In particular, the slow-wave mode is found to propagate within the resistivity-frequency range suited to the monolithic circuit technology, and its propagation mechanism is discussed. Approximate analysis of the fringing effect is also made for the slow-wave mode.

The growth of a space charge in bulk GaAs with a uniform doping profile but with a highly and three-dimensionally non-uniform electric field has been analyzed by introducing a concept of a "carrier current tube." From this analysis it has been shown how the behavior (i.e., growth or decay) of a small space charge depends upon the magnitude of an initial space charge, the nonuniformity of the field, and the dielectric relaxation time and that a space charge grows where the electric field changes along the carrier current even if no initial space charge exists. The "lateral spreading velocity" of a dipole domain has been estimated (its value is the order of 108cm/s) and its dependence upon the magnitude of an initial domain has been made clear. Furthermore, computer simulation have been performed for bulk GaAs devices with two-dimensional structure, such as a planar electrode, a nonuniform doping profile, and an imperfect cathode notch. The process of two-dimensional dipole domain formation in these devices has been made clear.

Current constriction in a p-n junction under a thermal mode of breakdown is analyzed and expressions for terminal voltage and radius of constriction are derived for silicon devices. The values predicted by this model are of the same order as those observed for transistors under second breakdown; it is proposed that second breakdown in transistors is a thermal mode of breakdown which inevitably follows if energy dissipated in the avalanche mode of breakdown is large enough to increase the temperature of some portion of the junction to the intrinsic or turnover temperature of the junction.

Current-voltage characteristics of the junction-gate field-effect transistor are analyzed based on a depletion layer model of the channel which is divided into subregions of constant mobility and of field-dependent mobility to reproduce the actual situation under various voltage conditions in order to clarify the effect of field-dependent mobility on the characteristics of the device. New formulas for design parameters are given and experimentally verified on specially designed and fabricated samples as well as on commercial samples. Agreement between theory and measurement is good.

The required trigger-pulse width and height for triggering a dipole domain in n-GaAs bulk devices were obtained analytically. Further switching properties of the three-terminal Gunn-effect digital devices have been made clear experimentally.